1. Field of the Invention
The present invention is broadly concerned with an improved projectible syringe designed to facilitate the injection of sedatives or other medicaments into animals from a position remote from the animal. More particularly, it is concerned with such a projectible syringe which can be readily filled and manipulated by the user, whereupon, through the use of a blow gun or similar device, the device can be projected toward and into the skin of a subject animal, with the dose of medicaments thereupon being injected, all without the necessity of the user coming into close proximity to the animal.
2. Description of the Prior Art
Those involved in the care of large animals (e.g., zoo keepers and livestock handlers) often find it convenient to sedate such animals. This allows the user to approach and care for the animal without fear that the animal will become aroused and perhaps dangerous. By the same token, it is sometimes desired to directly inject medicament into animals from a remote position.
It has been known in the past to provide a system including an elongated blow pipe together with a projectible syringe for such purposes. The syringe in this prior system is designed so that the injection needle thereof will pierce the skin of the animal and medicament will be thereupon injected by virtue of a charge of pressurized air established in the syringe prior to fixing thereof. Such a system is commercialized as the "Maxi-ject Veterinary Blowpipe System", and the overall structure of the blowpipe and syringe is described in an instruction manual distributed by Addison Biological Laboratory, Inc. of Fayette, Missouri. This instruction manual is incorporated by reference herein.
Basically speaking, the Maxi-ject apparatus includes an elongated syringe body having a pair of shiftable plungers therein. An injection needle is also provided which is adapted to fit onto one end of the syringe body. This needle is of specialized construction in that it includes a transverse aperture spaced from the sharpened skin-piercing needle end thereof which is in communication with an axial fluid passageway. A shiftable silicon sleeve is positionable over this transverse aperture, so that, when the syringe is projected into the animal's skin, the sleeve is shifted away from the aperture. This in turn permits the dose to be injected from the syringe by virtue of a previously established pressurized charge of air behind the injection plunger.
In practice however, the "Maxi-ject" apparatus requires the use of a conventional syringe in order to withdraw sedative or other medicament from a vial thereof, whereupon this conventional syringe is connected via a specialized coupler to the projectible syringe body. The fluid in the conventional syringe is then injected into the projectible syringe. The next step involves attachment of the specialized needle and flow-blocking sleeve onto the projectible syringe, followed by connection of a conventional air-filled syringe to the remote end of the projectible syringe body and filling the latter with a charge of compressed air between the two plungers. A guidance tail is then placed on the rear end of the projectible syringe remote from the needle, so as to complete the assembly and make it ready for use with the blowpipe. As can be appreciated, this procedure is rather complicated and unwieldly, particularly inasmuch as it is often necessary to carry out the make ready steps in the field. Accordingly, there is a real need in the art for an improved projectible syringe which can be readily filled and used without complicated procedures or extraneous equipment.